procengIV:
If you truly have a cryogenic process producing a gasified sales gas that is subsequently compressed by two compressors in series (that is what I think you write), then there is no engineering or process reason to treat your sales gas with any chemical. You may argue that the gas forms gums or self-reacts (polimerizes) within the compressor(s), but you haven't said that nor have you identified the "sales" gas by composition and temperature/pressure. I have never heard of a cryogenic plant that produces a gas that needs post chemical treatment before a compressor. That doesn't necessarily mean that one doesn't exist; but I want to know about it if it does exist. Post treatment downstream of a cryo plant is normally done for separation or upgrading of the product gas; the reason that I doubt need for a treatment downstream of a cryogenic plant is that if any treatment was really needed, if would logically be before the cryo plant - not after. Cryogenic plants are expensive, inaccessible, tightly designed, and sensitive to contaminants - PPMs of CO2 or water vapor will plug up a unit in no time at all.
Please give us all the detailed basic data; I can't speculate on what you have or operate. Perhaps with the data we can understand what you are proposing better.
Art Montemayor
Spring, TX